bcachefs: bch2_ioctl_subvolume_destroy() fixes

bch2_evict_subvolume_inodes() was getting stuck - due to incorrectly
pruning the dcache.

Also, fix missing permissions checks.

Reported-by: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
index e3a3230fc65284525807bfc151af6e65e358a78c..0273130f18dcdd59d5c5bd005ad14b62ecb344c3 100644 (file)
--- a/fs/bcachefs/fs-ioctl.c
+++ b/fs/bcachefs/fs-ioctl.c
@@ -541,10 +541,12 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
                ret = -ENOENT;
                goto err;
        }
-       ret = __bch2_unlink(dir, victim, true);
+
+       ret =   inode_permission(file_mnt_idmap(filp), d_inode(victim), MAY_WRITE) ?:
+               __bch2_unlink(dir, victim, true);
        if (!ret) {
                fsnotify_rmdir(dir, victim);
-               d_delete(victim);
+               d_invalidate(victim);
        }
 err:
        inode_unlock(dir);